Island



(No Model.)

2 Sheets-Sh eet 1. Y W. D. SHELDON.

TRAIN SIGNAL FOR RAILROADS.

No. 441,033. Patented Nov. 18', 1890."

WITNESSEE m: Nnams PETERS cm. mom-mam, WASHINGTON, D. c

(No Model.) 2 SheetsSheet 2.

- W. D. SHELDON.

TRAIN SIGNAL F03 RAILROADS. No. 441,033. Patented Nov. 18, 1890.

WINS/55555.. IN 17.322175: z%%o% W4 1- Mm waw/ NITED STATES PATENT OFFICE.

vVILLIAM D. SHELDON, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR TO NICHOLAS SHELDON, OF SAME PLACE.

TRAIN-SIGNAL FOR RAILROADS.

SPECIFICATION forming part of Letters Patent No. 441,033, dated November 18, 1890.

Application filed May 15, 1890.

To all whom it may concern.-

Be it known that 1, WILLIAM D. SHELDON, of the city of Providence, in the county of Providence and State of Rhode Island, have invented a new and useful Improvement in Train-Signals for Railroads; and I hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification.

This invention has reference to improvements in electric systems for lighting the tracks of railroads; and it consists in the peculiar and novel construction and arrangement of the electric-light circuit and the lamp in connection witha low-tension circuit operated by the passingtrain, so that the lights are automatically lighted and extinguished by the train, as will be more fully set forth hereinafter.

The invention further consists in the construction and arrangement of the circuits and the lamp by which an electric lamp secured above the center of the railroad track is lighted automatically in advance of the train, and a lamp placed at a considerable distance from the train will light a long distance of track in advance of the train, as will beinore fully set forth hereinafter.

The object of this invention is to light the track of a railroad by means of electric lamps with the greatest possible efficiency and at the lowest possible cost of construction and maintenance.

Figure 1 is a ground plan showing a section of a double-track railroad and my improved system of electric lighting. Fig. 2 is a perspective view showing one track of a railroad and my improved system for lighting the track. Fig. 3 is a side View of an arc lamp provided with means for short-circuiting the lamp and breaking the short circuit to light the lamp. Fig. 4 is a top View of the lamp, showing the relay or short circuit and the electro-magnet for breaking the short circuit.

Similar figures of reference indicate corresponding parts throughout.

[n the drawings, the number 6 indicates the rails of successive sections of a railroad-track.

$erial No. 351,951. (No model.)

The number 7 indicates a dynamo or other source of electric energy; 8, the conductorwires forming an electric-light circuit through a series of electric lamps 9, the poles 10 and 11 of which are each connected with the conductors 8. Each lamp is provided with a relay by means of which the lamps in their normal condition are short-circuited, as indicated in Fig. 1. The relay is shown on an enlarged scale in Fig. 4, and consists in the conductor-wire 12, connecting the pole 10 of the lamp with the hinged arm 13, held in the normal position by the spring 14 against the contact-point 15, connected with the pole '11 of the lamp, so that in the normal position the electric current will pass from one conductor-wire 8 to the other, through the conductor 12, the hinged arm 13, and contactpoint 15, instead of passing through the lamp. This short circuit is broken by energizing the electro-magnet 16 by the closing of a circuit, of which the conductor-wires 17 and 18, connected with the electro-magnet form the two arms, connected with a battery or other source of electric energy of a lower. tension than the electric-light circuit 8. These secondary or local circuits are divided into sections or blocks, each having a local battery or other source of electric energy, and a ground with which the circuit is connected, automatically, by a passing train, so that the short circuits on all the lamps of the block or section are broken automatically and the lamps lighted. In Fig. 1 these local circuits are shown connected with and operated by a track-circuit.

To enable others skilled in the art to prac tice my invention, I willmow describe the circuit-s more fully: The number 19 indicates a local batteryconnected at one end of the section or block with one rail by the short conductor 20 and by the lon er conductor 21 with the other rail. the block or section the elec ro-magnet 22 is connected by the conductor 23 with the rail 6 nearest the magnet, and by the conductor 24 with the other or outer rail 6, thus forming a closed circuit by which the electro-magnet' 22 is energized, and holds the hinged arm in contact with the electro-magnet While the circuit remains in this the normal condition.

Near he other end of Then a train enters the block or section, the wheels, resting on the rails 6 through the axle, connect the two rails, form a short circuit, and cut off the electric energy from the magnet 22, and the hinged arm 25 is drawn by the spring 26 against the contact-point 27, which contact-point is connected with the ground 28. When the train has left the section or block, the short circuit is removed, the current from the battery 19 passing through the two rails, and the conductors 20, 21, 23, and 24 energize the electro-magnet 22, and thereby draw the hinged arm 25 against the magnet, thus restoring the normal condition of the track-circuit.

The circuits by which the lamps on each section or block are lighted are connected with the track-circuit by means of the hinged arm 25, to the pivotal end of which the conductor-wire 18 is secured at one end, the other end being connected with the electromagnet 16 on one of the electric lamps. From this magnet 16 the conductor 17 extends toward the next lamp and becomes the conductor 18 as it reaches the magnet 16 of the next lamp. The conductor 17 extends from the electro-magnet 16 of this second lamp to the battery or other source of electric energy 29 to the ground 30. This second local circuit extends over the length of a section or block. The two electric lamps described as connected with this circuit are two lamps at opposite ends of the section or block. Any number of lamps required to light the roadbed of such a section or block may be placed 1 between these two lamps and connected in the circuit in exactly the same manner as the two lamps described are connected.

WVhen now the two rails of a section or block of track are connected by the wheels of a train and the hinged arm 25 is connected with the ground 28, as has been before described, then the electric energy from the battery or other source 29 energizes the magnets 16 of the lamps in the circuit, breaks the short circuit on these lamps by drawing the arm 13 against the magnet, thus lighting the lamps through which the electric-light cu rrent now passes.

The local section or block-circuit connected with the short circuit on the lamps is closed through the earth, as is indicated in broken lines, when the hinged arm 25 is in contact with the contact-point 27, and this circuit is broken when, the train having left the rails of the section or block, the track-circuit energizes the electro-magnet 22, and the hinged arm 25 is drawn away from the contact-point 27. The short circuits on the lamps are thus restored and the lamps extinguished.

The local circuits operating the lamp-cutcuts or short circuits overlap the track-circuits, so that a lamp or any number of lamps will be lighted in advance of the moving train and one or more lamps in the rear of the train.

Referring now to Fig. 2, the number 31 indicates the relay box or case, in which is 10- cated the electro-magnet 22, with the hinged arm 25 and contact-point for operating the local circuit by means of the track-circuit. The conductor-wire 18 is carried up on the lamp-pole 32, and extends to the next lamppole or lamp-poles, being supported on the intermediate poles 33. The lamps 9 are suspended from the horizontally-extending arm 34 at a point practically over the center, between the two rails 6 of the track, and are connected with the electric-light Wires 8 and with the local-circuit wires 18, as is shown in Figs. 1, 3, and 4:.

By practical tests and extended experi ments I have ascertained that a railroadtrack can be lighted for very long distances on the straight portions of a railroad by one electric-arc lamp when the lamp is placed over the track and practically over the center of the track. I find that with such lamps placed at very great intervals the track itself is so well lighted that the engineer can see the track, even at very great distances ahead, so distinct and clear that a small substance on the track will be seen by him. Ifind that the engineers attention is held to the two lines of light formed by the reflection on the two rails, and is not distracted by objects on each side of the track, as is the case when a head-light is used or when electric or other lights are placed on one side of the track.

I am aware that electric as well as other lights have been used to light streets by suspending the lamps over and at or near the center of the streets; but in such cases the lamps were placed at frequent intervals, and they did not and could not produce the peculiar and most valuable efiect produced by suspending an arc lamp over the center of a railroad-track to light'up a long distance of the rail by the reflection of the light on the rail, so as to give a clear view of the track, while the rest of the road-bed is in comparative darkness except near the lamp.

Having thus described my invention, I claim as new and desire to secure by Letters Patcut-- 1. The combination, with the track of a railroad and electric lamps placed over the track, of an electric-light circuit connected with opposite poles of the lamps, a short circuit connected with both poles of the lamps in the normal conditiomand a section or block circuit constructed to break the short circuit to light the lamps operated automatically by the passing train, as described.

2. The combination, with a dynamo or other source of electric energy, an electric light circuit the two arms of which extend along the two tracks of a double-track railroad, and electric lamps secured in the two arms of the electric-light circuit, of relays forming short cir cuits between the poles of each lamp, and local circuits connected with the electro-magnets of each relay,provided with a battery or other source of electric energy of a lower tension than the electric-lighj circuit, and with 4. The combinatioinwith the dynamo 7, the electric-light circuit 8, the lamps 9, each shortcircuited, as described, of the electro-magnets 16, the conductor-wires 17 and 18, the arms 13, the battery 29, grounds 30 and 28, and the electro-magnet 22 and arm 25, operated by the track-circuit, constructed to light and extinguish the lamp automatically by the passing train, as described.

WILLIAM D. SHELDON.

Witnesses:

S. F. B. MORSE, J. A. M1LLER,J1'. 

